Determination of geometry of thin, optically transparent layers e.g of mask or semiconductor wafer - simulating via computer model and using proportional relationship of intensity of reflection spectrum of thickness measurement at certain wavelength with integral of intensity distribution of densitometry measurement

摘要

Thin, optically transparent layers have inclined, curved or structured surface. From the determinant point of the surface both with a thickness (MD) measurement appts. is obtained a reflection spectrum and also with a densitometric width measurement appts. the intensity distribution of the reflex of the measurement beam is obtained via the measurement coordinates (X,Z). The two thus measured dependencies are reproduced via calculator models and the two part models are joined via the relationship that the intensity of the reflection spectrum at a specific wavelength is proportional to the integral of the intensity distribution of the densitometric measurement over the total measurement area at the same wavelength. USE/ADVANTAGE - Eg for nanometric nitride layer on silicon substrate, or in biology or medicine. Determines geometry of thin, optical transparent layers having pointed, curved or structured surfaces. Unambiguous determination of geometry.